Modeling of the adsorption breakthrough behaviors of 4-chlorophenol in a fixed bed of nano graphene oxide adsorbent

摘要

Continuous fixed-bed column studies were carried out using nano graphene oxide adsorbent for the removal of 4-chlorophenol in a contaminated aquatic solution. The adsorbents were characterized by X-ray diffraction analysis and scanning electron microscope analysis. Variables in the adsorption process were bed depths, (5, 10 and 15 cm), flow rate (1, 2 and 4 ml/min), influent 4-chlorophenol concentrations (5, 10, 15, 20 and 30 mg/l) and influent solution pH (6-7). The column sorption process was found to perform better at lower influent 4-chlorophenol concentration, lower flow rate and higher bed depth. The highest adsorption capacity (145.2 mg/g) on a 5 mg/l 4-chlorophenol solution was achieved within a flow rate of 1 ml/min and a bed depth of 15 cm. The results of this study have shown that 4-chlorophenol can be effectively adsorbed on nano graphene oxide. Thomas and Yoon-Nelson models were successfully used for predicting breakthrough curves for 4-chlorophenol removal by a fixed bed of nano graphene oxide using different flow rates and bed depths. The breakthrough time and exhaustion time decreased with increasing flow rate, decreasing bed depth and increasing influent 4-chlorophenol concentration.